Sear-disconnector mechanism



April 8, 1958 Filed April 14, 1955 W. B. BUTLER SEAR-DISCONNECTOR MECHANISM 2 Sheets-Sheet 1 FIGURE l IN V EN TOR.

I WALLACE B. BUTLER ATTORNEY v April 8, 1958 w. B. BUTLER sm -nxsqpunscwoa MECHANISM 2 Sheets-Sheet 2 Filed April 14, 1955 ACE B.BUTLER I B R m om N MERE 1 8 um m mm m #59". om mm 3 on @N a 8 ow mm mm A mm mm I 1/ g. A\\ 2 me N ing drawings, in which:

United Sta es fo 2,829,563 SEAR-DISCONNECTOR MECHANISM Wallace B. Butler, Branford, ,Conn. Appiication April 14, 1955, Serial No. 501,253

9 Claims. c1. s n-144 extraordinary safety mechanisms. Another object of this invention is to provide a semi-automatic firearm having the aforementioned featuresand yet inexpensive to manufacture by reason of its predominantly screw machine coustructability. Another object of this invention is to provide a semi-automatic firearm which employs a novel sear mechanism that engages and locks the firing pin striker automaticallyduring the recoil and reload stroke regardless of the position of the trigger.=- A further object of this invention is to provide a semi-automatic firearm having a novel combinedfiringpin-ejector arrangement for firing and ejecting each cartridge. 7 And a still further object of this invention is to provide a novel sear locking mechanism whichprevents firing'the gun when the bolt is in a non-battery position. Another object of this invention is to provide an inexpensive semi-automatic firearm wherein a novel sear mechanism, a novel sear locking mechanism and a novel firing-ejecting mechanism are combined to produce a gun of novel action. Other objects will become apparent to those skilled in the art upon reading the following detailed disclosure with accompany- Figure 1 is a fragmentary vertical longitudinal view of the semi-automatic rifie of this invention adapted for feeding from a box magazine. I

Figure 2 is a vertical cross-sectional view of the rifle shown in Figure 1 taken on line 22.

. Figure 3 is a fragmentary'horizontal longitudinal view taken on line 3-3 of the rifle shown in Figure 1.

' The firearm of this invention broadly comprises a receiver tube 11 having a recoil block 12 afiixed to its breech end. A barrel 13 is affixed to the open end of the receiver tube and held in proper position witha barrel locating pin 14, extending through the assembly just below the chamber section of the barrel. Afiixed to the top surface ofthe barrel is a rear sight 15 and a front sight 16.

The receiver tube contains a bolt 17 which is capable of reciprocal sliding movement within the tube cavity. The bolt contains in slidable engagement within its centermost cavity, a firing pin body 18 from. which extends a firing pin 19 of the rim-fire type. 'This firing pin is affixed to the outer surface of the firing pin body and I makes contact when the bolt is in battery position with the rim of the cartridge case contained in the chamber. The body 18 contains an axial shouldered cavity for containing a firing pin retractor spring 20 in the forward; section which spring loads the body to the rear. The

the recoil block.

2,829,563 Patented Apr. 8, 1958 ice spring rests itself between the front surface of the shoulder in the firing pin body and the rear surface of the cartridge seat face in the bolt. An ejector 21 of cylindrical shape, having a collar thereon at its midsection capable of reciprocable movement within the cavity of the body 18 protrudes centrally from the rear section through the retractor spring 20 and partially through an axial cavity within the cartridge seat face. Ejector spring 22 which encircles the rear portion of the ejector acts to spring load it forwardly. Diametrically across the, rear'opening of the firing pin body is ejector spring pin 23 which, contains the ejector spring 22 within the body. This assembly of firing pin body, firing pin and ejector combined makes for a floating arrangement having a smooth firingejecting action and provides for a reboundingfiring pin and to eject long, short, or long rifle cartridges.

Extending rearwardly from an upper longitudinal cavity in the bolt, is a cylindrical timing rod24 encircled by timing rod collar 27 held in place by retaining ring 28. When the bolt isrin battery condition, i. e., in a'completely forward position, the timing rod spring is in an initially compressed state. When the bolt 17 ismoved rearwardly either by recoil or by hand operation of the operating slide finger, it spring loads the rod to the rear, forcing its collar projecting portion 91 into a cavity within the sear to lock said sear 43 in a position whereby if the shooter attempts to pull the trigger when the bolt is opened, the timing rod will block the sear so that it cannot release the firing pin striker should the striker be in cocked position.

.In a horizontal slot, seen most clearly in Figure 3, within the bolt is an extractor 29 pivoted for movement around vertically disposed extractor pin 30. Extractor spring 31 as well as extractor cam follower 92 operated upon by a cam 93 in the firing pin body forces the ex- .tractor into claw engagement with the rim of the cartridge case 32 contained within the chamber section of the barrel. The extractor, upon rearward movement of the bolt, pulls the cartridge case by its rim to a point. Where it is ejected by the ejector through an ejection opening in the'side of the receiver tube, regardless of the length of the cartridge whether fired or not.

The bolt assembly is maintained in a forward position .by an operating slide 33 aflixed to the bolt and acted spring is disposed between slide guide stud 34 and a slide' frontal shoulder 37.

Extending from the recoilblock 12 is a striker 38 having an annular groove or cocking shoulder at 39 for engagement either with the cocking shoulders of the sear 43 or the disconnector 48 to permit cocking of said striker. Cooking is performed when the bolt is moved rearwardly causing the striker to be moved rearwardly by the firing pin body. Just before the striker reaches its rearmost position, its shoulder will be engaged by the sear 43 or by the disconnector 48 preventing forwardreturn until its groove. is released. When released by the disconnector, the striker will be driven forwardly until its shoulder is engaged by the sear. When released by the sear, it is again driven forwardly by the striker spring 40, until its striking head 41 hammers against the firing pin body. Under such action, the firing pin 19 is driven into the rim of the cartridge case 32 causing ignition of. the propellant contained therein. a

A novel sear mechanism is located within a vertically disposed cylindrical cavity 42 in the forward section of I It consists of. a rod having axially located holes drilled into each end (double cup shapebase to base) known as the sear 43. This sear is normally spring loaded downwardly by sear spring 44 which is contained within the upper cup of the sear. Within the forward facing wall of the upper cup of the sear is a cavity 45into which the collar projecting portion 91 of the timing rod 24 can enter. This, however, can only occur when the sear is in its most downward position and when the timing rod is spring loaded to the rear by the bolt in a non-battery position. When this occurs, a lock upon the sear results making the trigger inoperable until the bolt is again in battery position. The firing pin striker 38 extends through a horizontally disposed cavity 46 which has been drilled radially through the sear to cut through the base of its inverted cup portion. The upper surface of this cavity contains a scar shoulder 47 which can engage the annular groove or cocking shoulder 39 of the striker 38, when the bolt 17 cocks the striker rearwardly. Mounted within the inverted cup portion of the sear is a cup-shaped disconnector 48 having a perpendicular flaring lip portion. The disconnector is spring loaded upwardly by disconnector spring 49 in an initially compressed state (also operating as the trigger spring) mounted within the disconnector cavity and supported by the upper surface of the trigger 50. The scar at its lower end abuts against the flaring lip portion of the disconnector. By action of the sear spring, acting through the sear, the disconnector shoulder 51 is normally disengaged from the striker cocking shoulder 39. When the trigger 50 is pulled, it not only forces the sear 43 and the disconnector 48 upward but also compresses disconnector spring 49. Thus, should the trigger 50 be depressed during the arming stroke of the bolt 17 which prevents engagement of the sear shoulder 47 with the cocking shoulder 39, the disconnector shoulder 51 engages the striker 38 at its cocking shoulder due to the upward movement of the disconnector by force of the compressed disconnector spring. Subsequent release of the trigger will result in the disconnector moving downward by action of the compressed sear spring 44 out of engagement with the striker. The more forward sear shoulder 47 will then engage the striker and cocking continues.

Trigger 50 is pivoted to rotate vertically about trigger pin 52 mounted upon the lower portion of the recoil.

block. Trigger stop screw 53 extending downwardly from the receiver tube and trigger stop screw nut 54 control movement and adjustment of the trigger. The finger piece of the trigger is enclosed within a trigger guard 55, which may be of nylon or other plastic material.

The cartridge feed system employed with the rifle of the invention may consist of various types. Among the most popular of these are the box feed.

As shown in Figure 1 the magazine of the rifle consists of a magazine case 56 contained within a rectangular slot in the trigger guard 55. This case is kept in dispensing fashion to the bolt by magazine lock 57 pivoted on magazine locking pin 58 and held in locking engagement by magazine locking spring 59. Within the case is contained a magazine spring 60 at the lower forward portion of the magazine which spring loads magazine follower plunger 61 on top of which is magazine follower 62 upward. Thus as the uppermost cartridge 63 is re moved from the case, another is substituted from the supply column.

Rearwardly of the sear is located a trigger safety 80. It is made of a bar stock containing a notch 81 and rotates within annular cavity 82. A safety spring 83 and retaining ring 84 prevent endwise movement of the safety. Finger piece 85 permits operation of the safety by the thumb of the shooter which when rotated to the rear, the safety bar blocks the trigger so the trigger cannot be pulled.

The entire assembly, namely, the bolt and the receiver with all its component parts, is aflixe'd to a gun stock 86, by recoil block screw 87 and slide guide stud screw 88.

An operating slide finger 90 is, attached to the operating slide 33 to enable manual movement of the bolt rearwardly.

To safely operate the gun, the safety 38 should first be placed in an F or rear position by pulling the finger piece with rearward movement of the thumb. A loaded magazine, 56 is then placed into the gun. The operating slide finger piece is pulled rearwardly and released. A cartridge from the magazine is picked up by the bolt on the release or reload stroke movement and driven into the chamber section of the barrel. The gun is then aimed and the safety pushed forward to the fire position. When the sights are on target the trigger 50 'is pulled thereby raising the sear 43 which is turn releases the striker 38. The spring-loaded striker moves forward under the force of the striker spring 40. It strikes the firing pin body 18 which is spring loaded to the rear by the firing pin retractor spring 20. This striking force causes the firing pin to contact the rim of the cartridge case 32 contained in the chamber section of the barrel and ignites the cartridge. During this forward movement of the firing pin the ejector 21 is also moved forward until it contacts the central portion of the head of the cartridge, case whereupon it is restricted from further forward movement. An initial spring load is built up behind the ejector 21 by compression of the ejector spring 22.

As the projectile travels down the bore of the gun the cartridge case starts on its rearward blow back travel. The bolt 17, is therefore, forced to the rear. As the bolt is accelerated to the rear, it drives the striker 38 rearward against the force of the striker spring 40 which in turn is continually increasing the force that is being applied on the ejector. Also, during this rearward travel of the bolt, the timing rod spring 25 is being compressed thereby spring loading the timing rod 24 to the rear to force its collar against the sear 43. Should the sear be in its striker-engaging position (most downward position) the timing rod collar projecting end would have entered into groove 45 of the sear to prevent its upward movement. Hence, a lock is effected upon the sear and hence upon the trigger and it cannot be pulled so long as the bolt is in a non-battery condition. When in a battery condition the timing rod is no longer spring loaded and the sear is not engaged by said rod. The trigger can then be pulled. A gun which can only be safely fired results.

An increasing force upon the striker spring 40 also occurs as the bolt is accelerated to the rear on its blow back travel. Force against the striker head, through the firing pin body 18 causes compression of the ejector spring 22 which in turn is applying an increased force on the ejector 21 to force a long rifle or short cartridge fired or not fired to pivot around the extractor 29 and thereby eject itself out of the receiver as soon as the case clears the front wall of the ejection opening of the receiver.

When the bolt is within A of its fully rearward travel, the trigger may still be in a pulled position due to lag in reflex action of the shooter. Since the trigger may still be in a pulled position the sear 43 cannot engage the firing pin striker 38 to maintain it in a cocked position. To overcome this the disconnector 48 has been incorporated into the gun to engage the annular groove in the striker so long as the trigger is pulled. When release of the trigger occurs, the disconnector drops and the sear then engages the annular groove in the striker. Cooking of the pin is, therefore, maintained until the trigger is again pulled. By this arrangement a safe semi-automatic gun is enabled free of defects caused by the shooters reflex ability.

The bolt, after its rearward blow back or recoil travel is then moved forward in an arming or reload stroke by force of the compressed main spring 35 acting upon said bolt through operating slide 33. During this forward travel, the bolt cartridge face engages the rim of the next fed cartridge in the magazine case 56. This cartridge has presented itself to the cartridge face by being forced upward the' mag azine spring 60-. The cartridge is driven into the chamber section of the barrel 13 and the gun is again ready to fire.

As the bolt approaches within @040" of the closed battery position, the head 26 of the timing rod 24 is contactedby the bolt and is movedforward. The timing rod, is thereby moved out of engagement with the sear 43 so that the sear will not bev blocked when the bolt is .fullyhome, The shooter may now pull the trigger to cause safe firing.

Obviously, modifications may be made by those skilled in the art in the construction of the gun of this invention after reading this disclosure. Such obvious modificabarrel having a chamber section attached to said receiver,

a reciprocablebolt having an extractor attached thereto within said receiver, operated upon by a main spring,

a combined firing pin-ejector mechanism within an axial disposed cavity within the bolt actuated by a rod-shaped firing pin striker having a rearwardly disposed annular shoulder thereon, said striker extending through a longitudinal cavity within a sear-disconnector mechanism, said sear-disconnector mechanism being located in a vertically disposed cavity of the recoil block section of the receiver and comprising a'downwardly spring biased double cupshaped sear, the inverted cup of which contains an upwardly spring biased disconnector, said scar and said disconnector capable of engagement with the annular shoulder of the firing pin striker, a trigger for controlling said engagement of the scar and the disconnector to permit release of the cocked striker and a timing rod actuated by the bolt for controlling the operation of said sear.

2. A semi-automatic firearm comprising a receiver, a barrel having a chamber section attached to said receiver, a reciprocal tubular bolt having an extractor attached thereto within said receiver, operated upon by a main spring, and containing within a centrally disposed cavity a rearwardly spring biased tubular shaped firing pin-ejector body member, said member having a firing pin extending forwardly therefrom and containing a forwardly spring biased rod shaped ejector, projecting beyond said member and said member spring biasing means, a spring biased firing pin striker for causing engagement of the firing pin of said firing pin-ejector body member with the primer of a chambenenclosed cartridge and for increasing compression against the ejector as the bolt travels rearward on its blow back stroke thereby forcing the cartridge extracted by the extractor to pivot about said extractor and to be ejected from the receiver, said striker being of rod shape and having a rearwardly disposed annular shouder thereon and extending through a cavity within a sear-disconnector mechanism, said sear-disconnector mechansim being located in a vertical centrally disposed cavity of the recoil block section of the receiver and comprising a downwardly spring biased double cupshaped sear, the inverted cup of which contains an upwardly spring biased disconnector, said scar and said disconnector capable of engagement with the annular shoulder of the firing pin striker, a trigger for controlling said engagement of the sear and the disconnector to permit release of the firing pin striker and a timing rod actuated .by the bolt for controlling the operation of said sear.

3. A combined sear-disconnector mechanism for a semi-automatic firearm comprising a double cup shaped member containing two staggered shouldered members, each separately spring biased against a firing pin-striker of the firearm, said striker extending through a cavity within said cup shaped member and operated upon by the trigger of said firearm to cause their disengagement.

4. A combined sear-disconnector mechanism for a semi- 6. n j V automatic firearm comprising va double cup-shaped member having a diametrically disposed cavity extending through the base portion of one of the cups of said double cup-shaped member, said cavity containing a scar shoulder thereon for engagement with the cocking shoulder of a firing pin striker which extends therethrough, a scar spring for spring loading said cavity shoulder against the firing means, a disconnector of cup-shape slidably engaged within the base-perforated cup portion and having a shoulder on its base disposed rearwardly of said cavity shoulder, a disconnector spring for spring loading said disconnector against said firing pin striker for cocking engagement when the triggering means of the firearm is depressed, said triggering means operable upon said sear shoulder to disengage it from the cocking shoulder of said firing means.

5. In a semi-automatic firearm including a receiver, a trigger, a reciprocable bolt and a recoil block, the combination therewith of: a firing pin carried by said bolt,

a shouldered striker rod, one end of the striker rod being reciprocable within the bolt and the other end being carried by the recoil block, a sear assembly slidably mounted in the recoil block and having an aperture for receiving the striker rod therethrough, said assembly being movable along a line generally across to the path traversed by the striker, said sear assembly including at least two relatively movable shouldered members, each independently engageable with the shoulder on the striker rod and spring means cooperating with the trigger for urging said assembly into engagement with the striker rod.

6. In a semi-automatic firearm including a receiver, a trigger, a reciprocable bolt and a recoil block, the combination therewith of: a firing pin carried by said bolt, a shouldered striker rod, one end of the striker ro-d being reciprocable within the bolt and the other end being carried by the recoil block, a sear-disconnector mechanism slidably mounted in the recoil block and having an aperture for receiving the striker rod therethrough, said mechanism being movable along a line generally perpendicular springs for urging said relatively movable members into engagement with said striker rod.

7. In a firearm a firing mechanism comprising a shoul dered striker, a member reciprocable along a first axis, said member having an aperture for receiving the striker and a shoulder for engaging a shoulder on the striker, said striker being reciprocable along a second axis, a second member carried by said first member and relatively movable thereto, said second member having a shoulder for engaging the shoulder on the striker and resilient means for urging both said members toward said striker whereby at least one of said shouldered members engages the shoulder on the striker and blocks reciprocation of the striker.

8. In a firearm a firing mechanism comprising a reciprocable striker means, a generally cylindrical member, said member having at least one cylindrical cavity, a disconnector element disposed in the cavity and movable relative to said cylindrical member, said cylindrical element having a transverse aperture formed therein for receiving the reciprocable striker means, said cylindrical element, said striker means and said disconnector having cooperating shouldered portions formed thereon, spring means forurging the cylindrical element and the disconnector toward said striker whereby the shouldered portions thereof tend to engage the shoulder on the striker means to block reciprocation of the striker means.

9. In a firearm a firing mechanism comprising at least two relatively movable shouldered members, both said members being reciprocable along a first axis, a shouldered striker movable along a second axis and in a path which is generally transverse to said first axis, at least one of said shouldered members being formed with an aperture for receiving said striker whereby the shouldered portions of said members are adapted to engage the shoulder on the striker, spring means for urging said members toward said striker whereby the shoulder of one of said members engages the shoulder on the striker to block motion of the striker, and a rod reciprocable along a path generally parallel to said transverse path and engageable with said one of said members for retaining said member in the 1 blocking position.

UNITED STATES PATENTS Febiger July 29, 1913 Chevallier May 8, 1923 Browning May 3, 1938 Jones Nov. 15, 1938 Williams June 11, 1940 Sampson et a1. July 2, 1946 Williams Feb. 15, 1949 Harvey Oct. 16, 1951 

